Receptacle for grinder tools

ABSTRACT

The invention is based on a tool receiver for a grinder, in particular for a handheld angle grinder ( 10 ), having a carrier device ( 12, 14, 16, 182, 184, 300 ), via which an application tool ( 18, 32, 186, 188 ) can be actively connected to a drive shaft ( 54 ). 
     It is proposed that the application tool ( 18, 32, 186, 188 ) be actively connectable to the carrier device ( 14, 16, 182, 184 ) via at least one detent element ( 24, 26, 190, 192, 194, 196, 198, 200, 302 ) movable against a spring force that snaps into place in an operating position of the application tool ( 18, 32, 186, 188 ) and immobilizes the application tool ( 18, 32, 186, 188 ) with positive engagement.

BACKGROUND OF THE INVENTION

The invention is based on a tool for a grinder.

A tool receiver for a grinder for a handheld angle grinder is made knownin EP 0 904 896 A2. The angle grinder comprises a drive shaft thatcarries a thread on the tool side.

The tool receiver for a grinder comprises a carrier and a tensioningnut. To install a sanding disk, the carrier with an installation openingis pushed onto a collar of the drive shaft and tightened with positiveengagement against a bearing surface via the tensioning nut. The carrierhas a collar extending in the axial direction on the tool side thatcomprises radially-situated recesses on two opposite sides on its outercircumference that extend in the axial direction to a base of thecollar. Starting at the recesses, one groove each extends around theouter circumference of the collar against the driving direction of thedrive shaft. The grooves are closed against the driving direction of thedrive shaft and taper axially starting at the recesses against thedriving direction of the drive shaft.

The sanding disk comprises a hub having an installation opening in whichtwo tongues point radially inward on opposite sides. The tongues can beinserted in the recesses in the axial direction and then in the groovesin the circumferential direction, against the driving direction. Thesanding disk is immobilized in the grooves in the axial direction viathe tongues with positive engagement and in the tapering contour of thegrooves via non-positive engagement. During operation, the adhesionincreases as a result of reaction forces acting on the sanding disk,which counteract the driving direction.

In order to prevent the sanding disk from spinning off of the carrierwhen the brake is applied to the drive shaft, a stopper is located inthe vicinity of a recess on the circumference of the collar that issupported in an opening in a fashion that allows it to move in the axialdirection. In a working position with the sanding disk pointingdownward, the stopper is displaced axially in the direction of thesanding disk by means of the force of gravity, closes the groove in thedirection of the recess, and blocks movement of the tongue located inthe groove in the driving direction of the drive shaft.

SUMMARY OF THE INVENTION

The invention is based on a tool receiver for a grinder, in particularfor a handheld angle grinder, having a carrier device via which anapplication tool can be actively connected to a drive shaft.

It is proposed that the application tool be actively connectable to thecarrier device via at least one detent element movable against a springforce, which detent element snaps into an operating position of theapplication tool and immobilizes the application tool with positiveengagement. Due to the positive engagement, a high degree of reliabilitycan be achieved, and a simple and cost-effective, tool-free, rapidmounting system can be achieved. The application tool can be reliablyprevented from spinning off, even when the brake is applied to the driveshaft, which can result in high brake torques.

The detent element can immobilize the application tool with positiveengagement directly or indirectly via an additional component, forexample, via a locking lever or plunger, etc. that is supported in afashion that allows it to rotate and/or be displaced axially and iscoupled to the detent element. The detent element can immobilize theapplication tool directly and/or indirectly with positive engagement invarious directions, such as in the radial direction, in the axialdirection, and/or, particularly advantageously, in the circumferentialdirection. It is also possible that, due to the positive fixation of theapplication tool with the detent element in a first direction, e.g, inthe radial direction, the application tool is immobilized in a seconddirection with positive engagement by means of a component separatedfrom the detent element.

The movable detent element can be designed in various forms appearingpractical to one skilled in the art, e.g., as an opening, projection,peg, bolt, etc., and it can be located on the application tool or on thecarrier device.

Moreover, an advantageous encoding can be achieved by means of thepositive engagement, so that only specified application tools can besecured in the tool receiver for a grinder. The carrier device can bedesigned at least partially as a removable adapter part, or it can beconnected with the drive shaft in non-detachable fashion due to anon-positive, positive, and/or bonded connection.

Various application tools appearing practical to one skilled in the artcan be secured with the tool receiver for a grinder, such as applicationtools for separating, grinding, roughing, brushing, etc. A tool receiveraccording to the invention can also be used to secure a grinding plateof an eccentric grinding machine.

The spring force can be designed to act in various directions, such asin the circumferential direction or, particularly advantageously, in theaxial direction, whereby a solution can be achieved that is simple indesign. The spring force can further be used to immobilize theapplication tool in the circumferential direction as well as in theaxial direction.

In a further embodiment of the invention it is proposed that a drivetorque be transferrable via a positive connection between theapplication tool and the carrier device. A high drive torque can betransferred reliably, and a drive torque can be prevented from acting ona frictional connection.

As an advantage, the application tool can be connected to the carrierdevice via a carrier element located on the application tool and/or thecarrier device and extending in the axial direction, that can be guidedthrough at least one area of a slot of the correspondingcounter-element, displaced along the slot, and immobilized in an endposition by the detent element. Using the carrier element extending inthe axial direction, a securing in the circumferential direction and theaxial direction can be achieved, wherein the application tool isadvantageously immobilized with positive engagement in the axialdirection via a transfer surface of the carrier element. A high degreeof reliability can be achieved and additional components, weight,mounting effort, and costs can be achieved.

In one embodiment it is proposed that the detent element be formed by anelastically deformable component, wherein additional spring elements arespared, and simple, cost-effective designs can be achieved.

Advantageously, at least one detent element producing the spring forceis designed as an integral part of the tool hub of the application tool.The tool hub is usually produced out of a relatively thin material thatcan be designed with a simple construction that is elasticallydeformable. It is also feasible, however, that at least one springelement is designed as an integral part of a component of the carrierdevice, or it is formed by an additional component, wherein the tool hubcan be designed independent of a spring function.

In order to make a large spring deflection of the tool hub possible, atleast one recess is advantageously provided in a component of thecarrier device forming a bearing surface for the application tool, intowhich a part of the tool hub is elastically pressed in an operatingposition of the application tool.

In a further embodiment of the invention it is proposed that the slot beprovided in the tool hub of the application tool, and that at least onedetent element be formed by a part of the tool hub in the vicinity ofthe slot; in fact, particularly advantageously, the slot comprises awide area and at least one narrow area forming the detent element infront of an end position of the carrier element. Simple, cost-effectiveand, in particular, essentially flat tool hubs can be achieved that canbe handled easily and in space-saving fashion during manufacture andsubsequent storage without the tool hubs interlocking on top of eachother or with other objects. In addition to a narrowed area, however, anaxial raised part in the tool hub forming the detent element would alsobe feasible in principle.

It is further proposed that at least one detent element is supported ina fashion that allows it to move against a spring element. A largedisplacement of the detent element during mounting of the applicationtool can be achieved by means of the detent element supported in movablefashion, by way of which a large overlap between two correspondingdetent elements and a particularly reliable positive connection can beachieved on the one hand and, on the other, a very audible snap-in noisecan be achieved that signals to the user in advantageous fashion thatthe snap-in procedure was completed as desired.

The detent element can be designed to be movable in various directionsagainst a spring element, such as in the circumferential direction or,particularly advantageously, in the axial direction, by way of which asimple design can be achieved.

The detent element can even be supported in movable fashion in acomponent in a bearing, e.g., in a flange of the carrier device or in atool hub of the application tool. Advantageously, the detent element canalso be firmly connected to a component supported in movable fashion ina bearing in non-positive, positive, and/or bonded fashion, or it can bedesigned integrally connected with this, e.g., with a componentsupported on the drive shaft or a tool hub of the application tool.

If the detent element can be released from its locked position using arelease button and, in particular, if it is movable against the springelement, the snap-in connection can be reliably prevented from comingloose, e.g., by means of brake torque, and safety can be increased.Operation of the application tool in two circumferential directions canbe made possible in principle, and comfort during installation andremoval of the application tool can be increased.

If the application tool is connected to the carrier device in thecircumferential direction via at least a first element and, in the axialdirection via at least a second element, simple and cost-effective toolhubs can be achieved that can advantageously be designed flat in shape.An interlocking of the tool hubs during manufacture and storage can beprevented, and good handling of the application tool with its tool hubscan be achieved. Moreover, the components can be advantageously designedfor their function, i.e., either for immobilization in thecircumferential direction or immobilization in the axial direction. Theelements can be formed by a component or, advantageously, by separatecomponents. The tool hubs can be designed simply and advantageously witha closed centering hole, and a low-vibration movement of the applicationtool can be achieved. Moreover, by selecting a suitable diameter for thecentering hole, it can be ensured that application tools provided forthe tool receiver for a grinder according to the invention can besecured to traditional grinders via heretofore known fastening devices,and, in fact, via fastening devices in particular with which theapplication tool can be immobilized on the drive shaft with a tensioningnut and a tensioning flange against a bearing surface in the axialdirection with positive engagement and, in the circumferentialdirection, via non-positive connection.

Moreover, at least one detent element extending in the axial directioncan advantageously be snapped into place in a recess of a tool hub ofthe application tool corresponding to the detent element in an operatingposition of the application tool in the axial direction, and theapplication tool can be immobilized with positive engagement in thecircumferential direction. Using a means of attaining the object of theinvention having a simple design, an advantageous positive connectioncan be achieved in a circumferential direction and, preferably, in bothcircumferential directions. The detent element extending in the axialdirection can be formed by a separate bolt or an integrally-moulded pegthat is produced by means of a deep-drawing procedure, etc.

If at least one detent element is integrally-moulded to a discoidcomponent and/or if at least two elements for immobilizing theapplication tool in the axial direction are integrally-moulded to adiscoid component, additional components, mounting effort, and costs canbe spared. Moreover, compression connections between individualcomponents and weak points resulting therefrom can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages result from the following drawing description.Exemplary embodiments of the invention are presented in the drawing. Thedrawing, the description, and the claims contain numerous features incombination. One skilled in the art will also advantageously considerthe features individually and combine them into further practicalcombinations.

FIG. 1 is an angle grinder shown from above,

FIG. 2 is a driving flange shown from below,

FIG. 3 is the driving flange in FIG. 2 shown in a side view,

FIG. 4 is a tool hub of a cutoff wheel shown from below,

FIG. 5 is an enlarged view along the line V—V in FIG. 4,

FIG. 6 is a variant of FIG. 3,

FIG. 7 is a variant of FIG. 4,

FIG. 8 is a sectional view along the line VIII—VIII in FIG. 1 through analternative carrier device,

FIG. 9 is a tool hub shown from below,

FIG. 10 is a variant of FIG. 8,

FIG. 11 is an exploded diagram of a variant of FIG. 8,

FIG. 12 is a tool hub from FIG. 11 shown from above,

FIG. 13 is a sectional view along the line XIII—XIII in FIG. 12,

FIG. 14 is a release button from FIG. 11 shown from below,

FIG. 15 is a sectional view along the line XV—XV in FIG. 14,

FIG. 16 is a carrier element from FIG. 11 shown from below,

FIG. 17 is a carrier element from FIG. 16 shown from the side,

FIG. 18 is a sectional view along the line XVIII—XVIII in FIG. 16,

FIG. 19 is an exploded diagram of a variant of FIG. 10,

FIG. 20 is a sectional view through a carrier disk in FIG. 19 withintegrally-moulded bolts,

FIG. 21 is a side view of a sheet-metal plate in FIG. 19, and

FIG. 22 is a driving flange in FIG. 19 shown from below.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an angle grinder 10 from above having an electric motor—notshown in greater detail—located in a housing 96. The angle grinder 10can be guided via a first handle 98 extending in the longitudinaldirection and integrated in the housing 96 opposite to a cutoff wheel 18and via a second handle 102 extending at an angle to the longitudinaldirection secured to a drive housing 100 in the vicinity of the cutoffwheel 186.

Using the electric motor, a drive shaft 54 can be driven via a gearmechanism, not shown in greater detail, on its end pointing toward thecutoff wheel 186 of which a carrier device 182 is located (FIGS. 2 and3).

The carrier device 182 comprises a driving flange 256. The drivingflange 256 is screwed into place on the drive shaft 54 via a thread 258and, with a face 260 pointing in the direction 44 opposite to the cutoffwheel 186, extends to a collar 262 on the drive shaft 54. It would alsobe possible to connect a driving flange with a drive shaft innon-detachable fashion, or to design it integrated with a drive shaft.Three driving pins 202, 204, 206 are pressed into the driving flange 256that extend in the axial direction 38 over an axial bearing surface 264of the driving flange 256 for the cutoff wheel 186, and that are evenlyspaced in the circumferential direction. Heads are integrally-moulded onthe driving pins 202, 204, 206 on the ends pointing toward the cutoffwheel 186. The head has a larger diameter than the remaining part of thedriving pin 202, 204, 206 and forms a support surface 278 in thedirection of the driving flange 256. A centering hole 266 for the cutoffwheel 186 extending in the axial direction 38 is integrally-moulded inthe bearing surface 264.

The cutoff wheel 186 comprises a sheet-metal hub 228 (FIG. 4). Thesheet-metal hub 228 comprises a centering hole 268, via which the cutoffwheel 186 can be centered on the centering collar 266 of the drivingflange 256. The sheet-metal hub 228 is connected and pressed to agrinding means 114 via a riveted joint, which is not shown in greaterdetail. The sheet-metal hub 228 comprises three slots 214, 216, 218evenly spaced in the circumferential direction 34, 36, each of whichcomprises a wide area 244, 246, 248 produced by means of a bore hole,and a narrow area 270, 272, 274 extending in the circumferentialdirection 36.

A part of the sheet-metal hub 228 is designed as a spring shackle on oneend of the slot 214, 216, 218 opposite to the wide area 244, 246, 248,which spring shackle forms a detent element 190, 192, 194. Instead ofspring shackles integrally-moulded to the sheet-metal hub 228,spring-mounted driving pins could also be attached to the drivingflange.

When the cutoff wheel 186 with its sheet-metal hub 228 is placed on thedriving flange 256, the heads of the driving pins 202, 204, 206 areinserted through the wide areas 244, 246, 248 of the slots 214, 216,218. The sheet-metal hub 228 is oriented with its centering hole 268over the centering flange 266. By rotating the sheet-metal hub 228relative to the driving flange 256 against the driving direction 34, thespring shackles or the detent elements 190, 192, 194 move under theheads of the driving pins 202, 204, 206. The direction of rotation 36for securing the cutoff wheel 186 is opposite to the driving direction34 of the drive shaft 54. This ensures that the cutoff wheel 186 doesnot unintentionally come loose during operation. The heads of thedriving pins 202, 204, 206 glide over the lugs 276 of the springshackles or the detent elements 190, 192, 194 when rotated, and displacethem in the axial direction 44 toward the driving flange 256. When theheads have passed the lugs 276 or an operating position of the cutoffwheel 186 has been reached, the spring shackles spring back partially inthe axial direction 38 and grip behind the heads with positiveengagement. A snap-in noise produced thereby can serve to ensure theoperator that the sheet-metal hub 228 is locked in place as desired. Aremaining tension or spring force of the spring shackles presses thecutoff wheel 186 against the bearing surface 264 without play in theaxial direction 44.

The drive torque of the electric motor is transferred from the drivingflange 256 with positive engagement via the driving pins 202, 204, 206and via the spring shackles or via the detent elements 190, 192, 194 tothe sheet-metal hub 228. A brake torque that is produced and opposes thedrive torque is transferred with positive engagement from the heads ofthe driving pins 202, 204, 206 via the lugs 276 of the detent elements190, 192, 194 to the sheet-metal hub 228, and with frictional engagementfrom the bearing surface 264 to a corresponding bearing surface of thesheet-metal hub 228. The magnitude of the friction force thereby dependson the surface condition of the two bearing surfaces 264 and a clampingforce of the spring shackles, and can be adjusted accordingly via theseparameters. The cutoff wheel 186 is reliably prevented from spinningoff. So as to transfer particular high brake torques, a Velcroconnection or another type of positive-engagement connection can becreated between the bearing surfaces, for example.

To remove the cutoff wheel 186, the cutoff wheel 186 is rotated in thedriving direction 34 relative to the driving flange 256 so that theheads of the driving pins 202, 204, 206 glide over the lugs 276 of thedetent elements 190, 192, 194. When the driving pins 202, 204, 206 cometo rest in the wide areas 244, 246, 248 of the slots 214, 216, 218, thecutoff wheel 186 can be removed from the driving flange 256 in the axialdirection 38.

An alternative carrier device 184 having a corresponding cutoff wheel188 is shown in FIGS. 6 and 7. Components that essentially remain thesame are basically labelled with the same reference numerals in theexemplary embodiments shown. Moreover, the description of the exemplaryembodiment in FIGS. 1 through 5 can be referred to for the exemplaryembodiment in FIGS. 6 and 7.

The carrier device 184 comprises a driving flange 234. Three drivingpins 208, 210, 212 are pressed into the driving flange 234, which extendin the axial direction 38 over an axial bearing surface 232 of thedriving flange 234 for the cutoff wheel 188, and are spaced evenly inthe circumferential direction 34, 36. Heads are integrally-moulded withthe driving pins 208, 210, 212 on their ends pointing toward the cutoffwheel 188. The head has a larger diameter than the remaining part of thedriving pin 208, 210, 212 and forms a conical, tapering transfer surface226 in the axial direction 44 toward the driving flange 234. Recesses236 are provided in the bearing surface 232 in the vicinity of thedriving pins 208, 210, 212.

The cutoff wheel 188 comprises a sheet-metal hub 230 (FIG. 7). Thesheet-metal hub 230 comprises a centering hole 268, via which the cutoffwheel 188 can be centered on a centering collar 266 of the drivingflange 234. The sheet-metal hub 230 is connected and pressed to agrinding means 144 via a riveted joint, which is not shown in greaterdetail. The sheet-metal hub 230 contains three slots 220, 222, 224evenly spaced in the circumferential direction 34, 36, each of whichcomprises a wide area 238, 240, 242 produced by means of a bore hole,and a narrow area, each of which forms a detent element 196, 198, 200,in front of an end position 250, 252, 254 of the driving pins 208, 210,212.

When the cutoff wheel 188 with its sheet-metal hub 230 is placed on thedriving flange 234, the heads of the driving pins 208, 210, 212 areinserted through the wide areas 238, 240, 242 of the slots 220, 222,224. The sheet-metal hub 230 is oriented with its centering hole 268over the centering collar 266. When the sheet-metal hub 230 is rotatedagainst the driving direction 24 relative to the driving flange 234, thedriving pins 208, 210, 212 move in the curved slots 220, 222, 224. Thedirection of rotation 36 for securing the cutoff wheel 188 is oppositeto the driving direction 34 of the drive shaft 54. This ensures that thecutoff wheel 188 does not unintentionally come loose during operation.

When the sheet-metal hub 230 is rotated, the heads of the driving pins208, 210, 212 glide with their conical transfer surfaces 226 over thenarrowed areas or over the detent elements 196, 198, 200 of the slots220, 222, 225, each of them thereby pressing part of the sheet-metal hub230 axially in the recesses 236 of the bearing surface 232 of thedriving flange 234 provided for this in the vicinity of the slots 220,222, 224 in the direction 44 of the driving flange 234. When the cutoffwheel 188 has reached an operating position, or when the driving pins208, 210, 212 have reached their end position 250, 252, 254 having awidth slightly larger than the middle area of the slots 220, 222, 224,the detent elements 196, 198, 200 snap into place behind the heads ofthe driving pins 208, 210, 212 with positive engagement. In the endpositions 250, 252, 254, the sheet-metal hub 230 is displacedelastically by a defined amount by the conical transfer surfaces 226 ofthe driving pins 208, 210, 212. A remaining elastic clamping force ofthe sheet-metal hub 230 presses this against the bearing surface 232.The sheet-metal hub 230 is secured without play in the axial direction38, 44 with positive engagement.

The drive torque of the electric motor is transferred from the drivingflange 234 with positive engagement via the driving pins 208, 210, 212at the end of the slots 220, 222, 224 to the sheet-metal hub 230. Abrake torque that is produced and opposes the drive torque istransferred with positive engagement from the heads of the driving pins208, 210, 212 via the detent elements 196, 198, 200 to the sheet-metalhub 230, and with frictional engagement from the bearing surface 232 toa corresponding bearing surface of the sheet-metal hub 230. Themagnitude of the friction force thereby depends on the surface conditionof the two bearing surfaces 232 and a clamping force of the detentelements 196, 198, 200, and can be adjusted accordingly via theseparameters. The cutoff wheel 186 is reliably prevented from spinningoff.

To remove the cutoff wheel 188, the cutoff wheel 188 is rotated in thedriving direction 34 relative to the driving flange 234 so that theheads of the driving pins 208, 210, 212 glide over the detent elements196, 198, 200. When the driving pins 208, 210, 212 come to rest in thewide areas 238, 240, 242 of the slots 220, 222, 224, the cutoff wheel188 can be removed from the driving flange 234 in the axial direction38.

FIG. 8 shows a sectional view along the line VIII—VIII in FIG. 1 througha carrier device 12 that is an alternative to FIG. 2. The carrier device12 comprises a driving flange 82 pressed solidly to a side of a driveshaft 54 facing a cutoff wheel 18 and a driving disk 56 supported on thedrive shaft 54 in such a fashion that it can be displaced axiallyagainst a coil spring 20 located in the center.

Three pins 40 are pressed into the driving flange 82 that extend in theaxial direction 38 toward the cutoff wheel 18 over the driving flange 82and that are evenly spaced in the circumferential direction 34, 36. Eachof the pins comprises a head on its end pointing toward the cutoff wheel18 that has a larger diameter compared to a remaining part of the pin40, and, on a side facing the driving flange 82, a conical supportsurface 76 tapering in the axial direction 44. The driving flange 82forms an axial bearing surface 80 for the cutoff wheel 18 thatestablishes an axial position of the cutoff wheel 18 and in whichrecesses 84 are provided in the vicinity of the pins 40. Moreover, threeaxial through holes 104 are provided in the driving flange 82 that areevenly spaced in the circumferential directin 34, 36; in fact, onethrough hole 104 each is located between two pins 40 in thecircumferential direction.

Three bolts 24 are pressed in the driving disk 56 supported on the driveshaft 54 in axially displaceable fashion, which extend in the axialdirection 38 toward the cutoff wheel 18 over the driving disk 56 and areevenly spaced in the circumferential direction 34, 36. The driving disk56 is pressed against the driving flange 82 by the coil spring 20 in thedirection 38 toward the cutoff wheel 18. The bolts 24 extend through thethrough holes 104 and extend in the axial direction 38 over the drivingflange 82.

Moreover, the carrier device 12 comprises a release button 28 designedin the shape of a pot, located in the middle, on the side facing thecutoff wheel 18. The release button 28 comprises three segments 106evenly spaced in the circumferential direction 34, 36 and extending inthe axial direction 44 toward the axially movable driving disk 56 thatgrip through corresponding recesses 108 of the driving flange 82 and areconnected to the driving disk 56 in the axial direction 38 via a circlip110 secure the release button 28 from falling out. The release button 28is inserted in displaceable fashion into a ring-shaped recess 112 in thedriving flange 82 in the axial direction 38, 44.

The cutoff wheel 18 comprises a sheet-metal hub 52 that is solidlyconnected and pressed to a grinding means 114 via a riveted joint whichis not shown in greater detail (FIG. 9). The tool hub could also beproduced out of another material appearing practical to one skilled inthe art, such as plastic, etc. The sheet-metal hub 52 comprises threesequential holes 46, 48, 50 in the circumferential direction 34, 36, thediameter of which is slightly greater than the diameter of the bolts 24.Moreover, the sheet-metal hub 52 comprises three slots 64, 66, 68located in sequence in the circumferential direction 34, 36 andextending in the circumferential direction 34, 36, each of whichcomprises a narrow area 70, 72, 74 and a wide area 58, 60, 62 producedby means of a bore hole, the diameter of which is slightly larger thanthe diameter of the heads of the pins 40.

The sheet-metal hub 52 comprises a centering hole 116, the diameter ofwhich is advantageously selected so that the cutoff wheel 18 can also bemounted on a traditional angle grinder using a traditional mountingsystem with a mounting flange. A “downward compatibility” is ensured.

When mounting the cutoff wheel 18, the cutoff wheel 18 is slid with itscentering hole 116 onto the release button 28 and centered radially. Thecutoff wheel 18 is then rotated until the pins 40 grip in the wide areas58, 60, 62 of the slots 64, 66, 68 of the sheet-metal hub 52 providedfor this. By pressing the sheet-metal hub 52 against the bearing surface80 of the driving flange 82, the bolts 24 in the through holes 104 andthe driving disk 56 are displaced against a spring force of the coilspring 20 on the drive shaft 54 axially in the direction 44 opposite tothe cutoff wheel 18.

Rotating the sheet-metal hub 52 further against the driving direction 34displaces the pins 40 in the curved narrow areas 70, 72, 74 of the slots64, 66, 68. The pins 40 thereby press with their conical supportsurfaces 76 on the edges of the slots 64, 66, 68, and press themelastically into the recesses 84 of the driving flange 82. Thesheet-metal hub 52 is thereby pressed against the bearing surface 80 andimmobilized in the axial direction 38, 44.

In a final operating position of the cutoff wheel 18, the holes 46, 48,50 come to rest in the sheet-metal hub 52 via the through holes 104 ofthe driving flange 82.

The bolts 24 are displaced axially in the direction 38 of the cutoffwheel 18 by means of the spring force of the coil spring 20, snap intoplace in the holes 46, 48, 50 of the sheet-metal hub 52, and immobilizethem with positive engagement in both circumferential directions 34, 36.When they snap into place, a snap-in noise audible to the operator isproduced which signals to the operator that the tool is ready to use.

A drive torque of the electric motor of the angle grinder 10 can betransferred to the cutoff wheel 18 from the drive shaft 54 to thedriving flange 82 with non-positive engagement, and from the drivingflange 82 via the bolts 24 with positive engagement. The drive torque istransferred exclusively via the bolts 24, because the slots 64, 66, 68are designed so that the pins 40 do not come to rest at the narrow end70, 72, 74 of the slots when the bolts 24 are snapped into place.Moreover, a brake torque occurring during and after the electric motoris switched off and that is opposed to the drive torque can betransferred with positive engagement by the driving flange 82 to thecutoff wheel 18 via the bolts 24. The cutoff wheel 18 is reliablyprevented from unintentionally coming loose. An advantageous, evendistribution of forces and mass is achieved by means of the three bolts24 evenly spaced in the circumferential direction 34, 36.

The release button 28 is pressed to release the cutoff wheel 18 from theangle grinder 10. The driving disk 56 is thereby displaced with thebolts 24 via the release button 28 against the coil spring 20 in theaxial direction 44 opposite to the cutoff wheel 18, whereby the bolts 24move in the axial direction 44 out of their locked position or out ofthe holes 46, 48, 50 of the sheet-metal hub 52. The cutoff wheel 18 isthen rotated in the driving direction 34 until the pins 40 come to restin the wide areas 58, 60, 62 of the slots 64, 66, 68 and the cutoff disk18 can be removed from the driving flange 82 in the axial direction 38.After the release button 28 is released, the driving disk 56, the bolts24, and the release button 28 are pushed back to their initial positionsby means of the coil spring 20.

An exemplary embodiment with a carrier device 14 that is an alternativeto the exemplary embodiment in FIG. 8 is shown in FIG. 10. FIGS. 8 and 9can be referred to with regard for features and functions that remainthe same.

The carrier device 14 comprises a driving flange 90 pressed onto thedrive shaft 54. A collar 92 is integrally-moulded to a driving flange 90forming a bearing surface 88 for the cutoff wheel 18, via which collar92 the cutoff wheel 18 is centered radially in its state with thecentering hole 116 mounted. Radial forces can be advantageously absorbedby the driving flange 90 without stressing the release button 28.

In order to immobilize the cutoff wheel 18, moreover, three pins 42spaced evenly in sequence in the circumferential direction 34, 36 andextending in the axial direction 38 over the bearing surface 88 aresupported in the driving flange 90 in a fashion that allows them to bedisplaced in the axial direction 38 against one disk spring 86 in eachcase. Each of the pins 42 comprises a head on its end pointing towardthe cutoff wheel 18 that has a larger diameter than a remaining portionof the pin 42 and has a conical transfer surface 78 tapering in theaxial direction 44 on a side facing the driving flange 90, and a supportsurface 78 a extending in parallel to the bearing surface 88. When theheads of the pins 42 are inserted through the wide areas 58, 60, 62 ofthe slots 64, 66, 68, rotating the sheet-metal hub 52 against thedriving direction 34 causes the pins 42 to be displaced into the curvednarrow areas 70, 72, 74 of the slots 64, 66, 68. The pins 42 aretherefore displaced axially over the conical transfer surfaces 78against the pressure of the disk spring 86 in direction 38 until thesupport surfaces 78 a of the pins 42 overlap the edges of the slots 64,66, 68 in the curved narrow areas 70, 72, 74.

In the installed state, the disk springs 86 press the cutoff wheel 18against the bearing surface 88 via the support surfaces 78 a of the pins42. Instead of a plurality of disk springs 86, the pins can also beloaded via a common spring element, e.g., via a disk spring extendingover the entire circumference and not shown in greater detail. Theexemplary embodiment shown in FIG. 10 having the pins 42 supported inaxially displaceable fashion is suited in particular for thick and/oronly slightly elastically deformable tool hubs.

FIGS. 11 through 18 show a further exemplary embodiment having a carrierdevice 16. The carrier device 16 comprises a driving flange 118 securedto a drive shaft—not shown in greater detail—via a thread 120 (FIG. 11,FIGS. 16, 17, and 18). The driving flange could also be designedconnected to the drive shaft via a non-detachable connection, or itcould be designed as an integral part with this.

The driving flange 118 comprises three segments 122, 124, 126 andintermediate spaces 128, 130, 132 between them located in sequence inthe circumferential direction 34, 36 and extending in the axialdirection 38 to a cutoff wheel 32 (FIG. 16). Each of these segments 122,124, 126 comprises a groove 134, 136, 138 on its circumference that isclosed against the driving direction 34 in each case via a rotary stop140, 142, 144 and is open in the driving direction 34. Moreover, thedriving flange 118 comprises a bearing surface 180 that establishes anaxial position of the cutoff wheel 32. Moreover, the segments 122, 124,126 form a centering collar for the cutoff wheel 32, via which thecutoff wheel 32 can be centered.

In the installed state, a detent element 26 is connected to the drivingflange 118 via three snap-in pegs 146, 148, 150 spaced around thecircumference, that grip through corresponding recesses 158, 160, 162 ofthe driving flange 118 and grip radially outward behind the drivingflange 118 (FIGS. 11, 14, and 15). Three locking segments 152, 154, 156located in sequence in the circumferential direction 34, 36 andextending radially outward are integrally-moulded to the detent element26, which also forms a release button 30. A coil compression spring 22is located between the driving flange 118 and the detent element 26,against which the detent element 26 can be displaced relative to thedriving flange 118 in the axial direction 44 opposite to the cutoffwheel 32. The detent element 26 is thereby guided over radiallyoutwardly-pointing bearing surfaces 164, 166, 168 between the lockingsegments 152, 154, 156 in radially inwardly-pointing surfaces of thesegments 122, 124, 126 of the driving flange 118. To prevent the detentelement 26 from tilting and to achieve small bearing surfaces 164, 166,168, the bearing surfaces 164, 166, 168 are formed by projections 170extending radially outward (FIG. 14).

In the installed state, the locking segments 152, 154, 156 are locatedin the intermediate spaces 128, 130, 132 of the driving flange 118 andextend radially over a groove bottom of the grooves 134, 136, 138. In aninitial position before installation of the cutoff wheel 12, the lockingsegments 152, 154, 156 of the detent element 26 lie in front of thegrooves 134, 136, 138, loaded by the preloaded coil compression spring22, in fact.

The cutoff wheel 32 comprises a ring-shaped sheet-metal hub 94 that ispress-moulded with a grinding means 114 on its outer diameter andcomprises tongues or spring elements 172, 174, 176 pointing radiallyoutward on its internal diameter (FIGS. 11, 12, and 13). The springelements 172, 174, 176, in combination with the driving flange 118 andthe release button 30, serve to transfer the drive torque, to axiallyposition the cutoff wheel 32, and to secure the cutoff wheel 32 fromspinning off when the electric motor is switched on or when the brake isapplied to the drive shaft. Moreover, the spring elements, in additionto the segments 122, 124, 126, can be used to center the cutoff wheel 32to the drive shaft.

When the cutoff wheel 32 is installed, it is oriented on the drivingflange 118 in such a fashion that the spring elements 172, 174, 176 onthe internal diameter of the sheet-metal hub 94 point into theintermediate spaces 128, 130, 132 between the segments 122, 124, 126 onthe driving flange 118. The spring elements 172, 174, 176 of the cutoffwheel 32 lie on the locking segments 152, 154, 156 of the release button30. The cutoff wheel 32 is then pressed in the axial direction until itreaches the bearing surface 180 of the driving flange 118. The springelements 172, 174, 176 displace the release button 30 with their lockingsegments 152, 154, 156 against the spring force of the coil compressionspring 22 in the direction 44 axially opposite to the cutoff wheel 32.The locking segments 152, 154, 156 are pressed into recesses 178 of thedriving flange 118 (FIG. 18) so that the spring elements 172, 174, 176come to rest in front of the grooves 134, 136, 138.

The cutoff wheel 32 is thereby centered radially via the centeringcollar formed by the segments 122, 124, 126. When the cutoff wheel 32 isturned against the driving direction 34, the spring elements 172, 174,176 grip into the grooves 134, 136, 138 of the driving flange 118. Aspring-groove connection is established. The spring elements 172, 174,176 comprise the length of the grooves 134, 136, 138 in thecircumferential direction 36. If the spring elements 172, 174, 176 arepushed into the grooves 134, 136, 138 completely, or if an operatingposition of the cutoff disk 32 is reached, the detent element 26 snapsinto place with its locking segments 152, 154, 156, wherein the coilcompression spring 22 presses the detent element 26 with its lockingsegments 152, 154, 156 into its initial position, so that the lockingsegments 152, 154, 156 come to rest in front of the grooves 134, 136,138 once more. The detent element 26, with its locking segments 152,154, 156, immobilizes the cutoff wheel 32 against the driving direction34 with positive engagement.

A snap-in noise that is audible to the operator is produced during thesnap-in procedure that signals to the user that the snap-in procedurewas completed as desired and the tool is ready to use.

The drive torque is transferred with positive engagement via the rotarystops 140, 142, 144 of the driving flange 118 to the spring elements172, 174, 176 of the sheet-metal hub 94 or the cutoff wheel 32. Thecutoff wheel 32 is centered via the centering collar formed by thesegments 122, 124, 126 of the driving flange 118 and is held in itsaxial position by means of the bearing surface 180 and the grooves 134,136, 138. Moreover, a brake torque occurring during and after the theelectric motor is switched off that opposes the drive torque istransferred with positive engagement from the locking segments 152, 154,156 and the driving flange 118 to the spring elements 172, 174, 176 ofthe cutoff wheel 32.

A compensation for play is achieved in the axial direction by means of aspring element—not shown in greater detail—formed by a metal strip inthe grooves 134, 136, 138. Moreover, a compensation for play could beachieved via other spring elements appearing practical to one skilled inthe art, such as via spring-loaded balls that are located in suitablelocations of the driving flange and that immobilize the tool hub of thecutoff wheel without play, and/or via a slight oversizing of the springelements of the tool hub, by means of a slightly wedge-shaped form ofthe grooves and the spring element of the tool hub, etc.

To release the cutoff wheel 32, the release button 30 is pressed in theaxial direction 44 opposite to the cutoff wheel 32. The locking segments152, 154, 156 of the release button 30 or the detent element 26 arepushed into the recesses 178 of the driving flange 118. The cutoff wheel32 can then be rotated in the driving direction 34 with its springelements 172, 174, 176 out of the grooves 134, 136, 138 of the drivingflange 118 and removed in the axial direction 38. When the cutoff wheel32 is removed, the release button 30 is pressed back into its initialposition by the coil compression spring 22.

An exemplary embodiment having a carrier device 300 that is analternative to the exemplary embodiment in FIG. 10 is shown in FIG. 19.The carrier device 300 comprises a driving flange 90 that forms abearing surface 88 for a cutoff wheel that is not shown in greaterdetail. A collar 92 is integrally moulded to the carrier flange 90 onthe side facing the cutoff disk, via which the cutoff disk is centeredradially with its centering hole in the installed state. Radial forcescan be advantageously absorbed by the driving flange 90 withoutstressing the release button 28.

A sheet-metal plate 308 having three integrally-moulded fasteningelements 306 extending in the axial direction 38 and spaced evenly inthe circumferential direction are located on a side of the drivingflange 90 opposite to the cutoff wheel to lock the cutoff wheel in placeaxially. The fastening elements 306 are integrally-moulded to thesheet-metal plate 308 in a bending procedure.

During installation, the driving flange 90, an undulate washer 312, andthe sheet-metal plate 308 are preassembled. The undulate washer 312 isthereby slid onto a collar 322 of the driving flange 90 pointing in thedirection opposite to the cutoff wheel. The fastening elements 306 ofthe sheet-metal plate 308, which comprise a hook-shaped extension on itsexposed end with an angled surface 310 pointing in the circumferentialdirection (FIGS. 19 and 21), are guided in the axial direction 38through recesses 314 in the driving flange 90, in fact, each of themthrough widened areas 316 of the recesses 314 (FIGS. 19 and 21). Bycompressing and rotating the sheet-metal plate 308 and the drivingflange 90 against each other, the undulate washer 312 is preloaded, andthe sheet-metal plate 308 and the driving flange 90 are connected withpositive engagement in the axial direction 38, 44, in fact, by thehook-shaped extensions rotating in narrow areas 318 of the recesses 314(FIGS. 19, 21, and 22). The sheet-metal plate 308 is then supported,loaded by the undulate washer 312, on the bearing surface 88 of thedriving flange 90 via edges 310 a of the hook-shaped extensions thatpoint axially in the direction opposite to the cutoff wheel.

After the sheet-metal plate 308 with the integrally-moulded fasteningelements 306, the undulate washer 312, and the driving flange 90 arepreassembled, a compression spring 20 and a driving disk 304 havingthree integrally-moulded bolts 302 extending in the axial direction 38and spaced evenly around the circumference are slid onto a drive shaft54. The bolts 302 are integrally-moulded to a sheet-metal plate formingthe driving disk 304 in a deep-drawing process (FIG. 20).

The preassembled assembly consisting of the sheet-metal plate 308, theundulate washer 312 and the driving flange 90 are then mounted on thedrive shaft 54. During installation, the bolts 302 are guided throughrecesses 320 integrally-moulded on the circumference of the sheet-metalplate 308 and through through holes 104 in the driving flange 90 andgrip through the through holes 104 in the installed state. Thesheet-metal plate 308 and the driving flange 90 are secured via thebolts 302 against rotating in relation to each other.

The driving flange 90 is pressed onto the drive shaft 54 and thensecured with a retaininer ring not shown in further detail. In additionto a compression connection, other connections appearing practical toone skilled in the art are also feasible, such as a threaded connection,etc.

When, during mounting of a cutoff wheel 18 (refer to FIGS. 8 and 10),the hook-shaped extensions of the fastening elements 306 are guidedthrough the wide areas 58, 60, 62 of the slots 64, 66, 68 of thesheet-metal hub 52 (FIG. 19), rotating the sheet-metal hub 52 againstthe driving direction 34 causes the hook-shaped extensions to be pushedinto the curved, narrow areas 70, 72, 74 of the slots 64, 66, 68 of thesheet-metal hub 52. In doing so, the sheet-metal plate 308 with thefastening elements 306 is displaced axially via the angled surfaces 310against the pressure of the undulate washer 312 in direction 38 untilthe edges 310a of the hook-shaped extensions come to rest in curved,narrow areas 70, 72, 74 laterally next to the slots 64, 66, 68 of thesheet-metal hub 53. In the installed state, the undulate washer 312presses the cutoff wheel 18 against the bearing surface 88 via the edges310 a of the hook-shaped extensions.

As an alternative, the fastening elements and the slots can be designedrotated by 180° in the sheet-metal hub, so that the mounting directionreverses, and the sheet-metal hub is rotated in the driving directionduring mounting. If the fastening elements are designed rotated by 180°,an angled surface of a lower front edge of the fastening element leadsduring operation, so that injuries by a front edge can be prevented.

Reference Numerals 10 Angle grinder 12 Carrier device 14 Carrier device16 Carrier device 18 Application tool 20 Spring element 22 Springelement 24 Detent element 26 Detent element 28 Release button 30 Releasebutton 32 Application tool 34 Circumferential direction 36Circumferential direction 38 Direction 40 Fastener 42 Fastener 44Direction 46 Recess 48 Recess 50 Recess 52 Tool hub 54 Drive shaft 56Component 58 Area 60 Area 62 Area 64 Slot 66 Slot 68 Slot 70 Area 72Area 74 Area 76 Seating surface 78 Transfer surface 80 Bearing surface82 Component 84 Recess 86 Spring element 88 Bearing surface 90 Component92 Collar 94 Tool hub 96 Housing 98 Handle 100 Drive housing 102 Handle104 Through hole 106 Segment 108 Recess 110 Circlip 112 Recess 114Grinding means 116 Centering hole 118 Driving flange 120 Thread 122Segment 124 Segment 126 Segment 128 Intermediate space 130 Intermediatespace 132 Intermediate space 134 Groove 136 Groove 138 Groove 140 Rotarystop 142 Rotary stop 144 Rotary stop 146 Snap-in peg 148 Snap-in peg 150Snap-in peg 152 Locking segment 154 Locking segment 156 Locking segment158 Recess 160 Recess 162 Recess 164 Bearing surface 166 Bearing surface168 Bearing surface 170 Projection 172 Spring element 174 Spring element176 Spring element 178 Recess 180 Bearing surface 182 Carrier device 184Carrier device 186 Application tool 188 Application tool 190 Detentelement 192 Detent element 194 Detent element 196 Detent element 198Detent element 200 Detent element 202 Carrier element 204 Carrierelement 206 Carrier element 208 Carrier element 210 Carrier element 212Carrier element 214 Carrier element 216 Slot 218 Slot 220 Slot 222 Slot224 Slot 226 Transfer surface 228 Component 230 Component 232 Bearingsurface 234 Component 236 Recess 238 Area 240 Area 242 Area 244 Area 246Area 248 Area 250 End position 252 End position 254 End position 256Driving flange 258 Thread 260 Face 262 Collar 264 Bearing surface 266Centering collar 268 Centering hole 270 Area 272 Area 274 Area 276 Lug278 Seating surface 300 Carrier device 302 Detent element 304 Component306 Element 308 Component 310 Angled surface 310a Edge 312 Springelement 314 Recess 316 Area 318 Area 320 Recess 322 Collar

1. Tool receiver for a grinder, in particular for a handheld anglegrinder (10), having a carrier device (300) via which an applicationtool (18) can be connected to a drive shaft (54) of the grinder (10);said carrier device (300) comprising at least one detent element (302),whereby said detent element (302) can be moved against a spring forceand said detent element (302) snaps into place in an operating positionof the application tool (18) driven by said spring force in order toimmobilize said application tool (18) in a circumferential direction,wherein the carrier device (300) comprises at least a second element(306) and a first spring element (312), whereby the second element (306)is separate from said detent element (302) and is designed to connectthe application tool (18) in an axial direction (44, 38) to the driveshaft (54) and whereby the first spring element (312) is designed toexert an axial force on the application tool (18) via the second element(306).
 2. Tool receiver for a grinder according to claim 1, wherein saidspring force acts in the axial direction (36).
 3. Tool receiver for agrinder according to claim 1, wherein said first spring element (312) isrealized as an undulate washer.
 4. Tool receiver for a grinder accordingto claim 1, wherein said axial force pulling the application tool (18)towards a body of the grinder (10).
 5. Tool receiver for a grinderaccording to claim 2, wherein said spring force is generated by a secondspring element (20) separate from the first spring element (312). 6.Tool receiver for a grinder according to claim 1, wherein said firstspring element (312) is preloaded during a connecting movement of saidapplication tool (18) relative to the carrier device (300).
 7. Toolreceiver for a grinder according to claim 4, wherein said carrier device(300) comprising an angled surface (310) used to preload said firstspring element (312) during the connecting movement.
 8. Tool receiverfor a grinder according to claim 4, wherein said first spring element(312) is preloaded during a part of the connecting movement directed ina circumferential direction.
 9. Tool receiver for a grinder according toclaim 1, wherein said first spring element (312) blocks in the operatingposition of the application tool (18).
 10. Tool receiver for a grinderaccording to claim 1, wherein the detent element (302) can be releasedfrom its locked position using a release button (28).
 11. Tool receiverfor a grinder according to claim 1, wherein the second element (306) isdesigned to be hooked into a recess (314) in the application tool (18).12. Tool receiver for a grinder according to claim 1, wherein at leastone detent element (302) is integrally molded on a discoid component(304).
 13. Tool receiver for a grinder according to claim 2, wherein atleast two elements (306) for immobilizing the application tool (18) inthe axial direction are integrally molded to a discoid component (304).14. Application tool having a tool hub (52) that can be effectivelyconnected to carrier device (300) and to a drive shaft (54) of a grinder(10), said tool hub (52) having at least one recess (46, 48, 50)designed to receive a detent element (302) of the carrier device (300)fixing the application tool in a circumferential direction to the driveshaft (54), wherein the tool hub (52) has at least a second recess (64,66, 68) designed to engage with a second element (306) of the carrierdevice, said second element (306) fixing the tool hub (52) in an axialdirection (44, 38) to said drive shaft (54).
 15. Application toolaccording to claim 14, wherein at least one of maid recesses (64, 66,68) is formed by a slot that comprises a wide area (58, 60, 62) and atleast one narrow area (70, 72, 74).
 16. Application tool according toclaim 14, wherein the tool hub (52) has a third recess (116) forcentering, which is separate from the first and the second recesses (46,48, 50, 64, 66, 68).